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Posted to dev@felix.apache.org by "Fabian Lange (JIRA)" <ji...@apache.org> on 2016/10/04 06:18:21 UTC

[jira] [Commented] (FELIX-5247) Reduce number of threads created by Resolver during a startup of OSGi-based applications

    [ https://issues.apache.org/jira/browse/FELIX-5247?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15544488#comment-15544488 ] 

Fabian Lange commented on FELIX-5247:
-------------------------------------

I filed a ticket for karaf and proposed a solution in https://issues.apache.org/jira/browse/KARAF-4748
which is in my opinion the right place for a fix of what the OP reported. IMHO this issue can be closed.

> Reduce number of threads created by Resolver during a startup of OSGi-based applications
> ----------------------------------------------------------------------------------------
>
>                 Key: FELIX-5247
>                 URL: https://issues.apache.org/jira/browse/FELIX-5247
>             Project: Felix
>          Issue Type: Improvement
>          Components: Framework, Resolver
>    Affects Versions: framework-5.4.0, resolver-1.8.0
>            Reporter: Dmitry Konstantinov
>              Labels: performance
>         Attachments: karaf_thread_creation.png
>
>
> Thread creation is a quite expensive operation, so it make sense to reuse threads in ResolverImpl if they are needed to split some task and do it in parallel.
> For example: Apache Karaf startup with several features can install about 300 bundles. If each one will create Runtime.getRuntime().availableProcessors() threads - so, during a startup about 1000 threads will be created only by Resolver (in case of a server machine even much more). Thread creation takes let's say (depends on machine, JDK, OS, etc) about 10-20 ms, so we are spending about 1-2 seconds of startup time only to create some threads.
> it make sense to create a thread pool once (with a configurable thread number) and reuse it for resolving of different bundles.
> Threads creation, stack examples:
> {noformat}
> java.lang.Thread.<init>(ThreadGroup, Runnable, String, long) Thread.java
> java.util.concurrent.Executors$DefaultThreadFactory.newThread(Runnable) Executors.java:613
> java.util.concurrent.ThreadPoolExecutor$Worker.<init>(ThreadPoolExecutor, Runnable) ThreadPoolExecutor.java:612
> java.util.concurrent.ThreadPoolExecutor.addWorker(Runnable, boolean) ThreadPoolExecutor.java:925
> java.util.concurrent.ThreadPoolExecutor.execute(Runnable) ThreadPoolExecutor.java:1357
> org.apache.felix.resolver.ResolverImpl$EnhancedExecutor.execute(Runnable) ResolverImpl.java:2436
> org.apache.felix.resolver.ResolverImpl$1Computer.run() ResolverImpl.java:1150
> org.apache.felix.resolver.ResolverImpl$EnhancedExecutor$1.run() ResolverImpl.java:2442
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor$Worker) ThreadPoolExecutor.java:1142
> java.util.concurrent.ThreadPoolExecutor$Worker.run() ThreadPoolExecutor.java:617
> java.lang.Thread.run() Thread.java:745
> {noformat}
> {noformat}
> java.lang.Thread.<init>(ThreadGroup, Runnable, String, long) Thread.java
> java.util.concurrent.Executors$DefaultThreadFactory.newThread(Runnable) Executors.java:613
> java.util.concurrent.ThreadPoolExecutor$Worker.<init>(ThreadPoolExecutor, Runnable) ThreadPoolExecutor.java:612
> java.util.concurrent.ThreadPoolExecutor.addWorker(Runnable, boolean) ThreadPoolExecutor.java:925
> java.util.concurrent.ThreadPoolExecutor.execute(Runnable) ThreadPoolExecutor.java:1357
> org.apache.felix.resolver.ResolverImpl$EnhancedExecutor.execute(Runnable) ResolverImpl.java:2436
> org.apache.felix.resolver.ResolverImpl.calculatePackageSpaces(Executor, ResolverImpl$ResolveSession, Candidates, Collection) ResolverImpl.java:1158
> org.apache.felix.resolver.ResolverImpl.checkConsistency(Executor, ResolverImpl$ResolveSession, List, List, Candidates, Map, Map, boolean) ResolverImpl.java:471
> org.apache.felix.resolver.ResolverImpl.resolve(ResolveContext, Executor) ResolverImpl.java:347
> org.apache.felix.resolver.ResolverImpl.resolve(ResolveContext) ResolverImpl.java:158
> org.apache.felix.framework.StatefulResolver.resolve(Set, Set) StatefulResolver.java:431
> org.apache.felix.framework.Felix.resolveBundleRevision(BundleRevision) Felix.java:4118
> org.apache.felix.framework.Felix.startBundle(BundleImpl, int) Felix.java:2124
> org.apache.felix.framework.BundleImpl.start(int) BundleImpl.java:998
> org.apache.felix.framework.BundleImpl.start() BundleImpl.java:984
> org.apache.karaf.features.internal.FeaturesServiceImpl.startBundle(InstallationState, Bundle) FeaturesServiceImpl.java:520
> org.apache.karaf.features.internal.FeaturesServiceImpl.installFeatures(Set, EnumSet) FeaturesServiceImpl.java:478
> org.apache.karaf.features.internal.FeaturesServiceImpl.installFeature(Feature, EnumSet) FeaturesServiceImpl.java:419
> org.apache.karaf.features.internal.FeaturesServiceImpl.installFeature(String, String, EnumSet) FeaturesServiceImpl.java:394
> org.apache.karaf.features.internal.FeaturesServiceImpl.installFeature(String, EnumSet) FeaturesServiceImpl.java:364
> {noformat}



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